By Slash Lane

Published: 10:30 AM EST

AT&T plans to offer faster wireless data connections on its 3G network to customers, including iPhone users, when it enables High Speed Packet Access 7.2 technology in a half-dozen cities by the end of 2009.

The upgrade delivers theoretical peak speeds twice that of the carrier's existing 3G network. Deployment will begin in Charlotte, N.C.; Chicago, Ill.; Dallas, Tex.; Houston, Tex.; Los Angeles, Calif.; and Miami, Fla. By the end of 2010, AT&T intends to have HSPA 7.2 available in 25 of the nation's 30 largest markets. And by the end of 2011, the nation's second-largest wireless carrier hopes to have the higher speed data available for 90 percent of its existing 3G coverage areas.

"Our deployment of HSPA 7.2 and supporting backhaul connectivity will enable our customers to continue to ride the leading edge of emerging devices and thousands of mobile applications," said John Stankey, president and CEO, AT&T Operations. "Our network is based on the predominant technology platform used by operators worldwide and has been tested by today's most popular devices. That experience gives us an important advantage in developing and deploying new technologies to meet customers' future needs."

The new network speeds will allow iPhone 3GS users to take full advantage of their device, allowing theoretical download speeds of up to 7.2Mbps. In all, AT&T plans to have six HSPA 7.2-compatible phones available for customers on its network by the end of the year, as well as two LaptopConnect cards.

AT&T said that it will also be performing significant upgrades to its "wireless backhaul" in the process, allowing the network to support HSPA 7.2 and 4G LTE -- the next generation of wireless broadband, expected to begin its roll out in 2011.

"With HSPA 7.2, we're making the nation's fastest 3G network even faster, and we'll be able to deploy this technology before LTE networks, devices and equipment grow to scale," Stankey said. "Even as we look forward to LTE, we know that 3G will be the predominant mobile broadband network technology worldwide for smartphones for the next few years. AT&T's strategy will deliver faster 3G speeds, while also allowing us to build the foundation for the 4G future."

In recent weeks, AT&T has announced its intentions to spend more than $17 billion on improving its network this year alone. The carrier recently strengthened its 3G signal in the New York-New Jersey Tri-State Region, and plans nearly 1,900 new cell towers to be built across the country this year.

In the face of network troubles partially caused by the bandwidth-guzzling iPhone -- dubbed the "Hummer of cellphones" in a New York Times article -- AT&T has fought back in an attempt to improve its image as customers online voice complaints.

The exclusive carrier of the iPhone in the U.S. announced last week that multimedia messaging capabilities would be enabled for the iPhone 3G and iPhone 3GS on Sept. 25. The company has not announced when it will make tethering the iPhone data connection with other devices available.